Humankind has come a long way from the days when simple foot travel (i.e., walking and running) were the only means available for people to move from one location to another. Terrain that previously required months to traverse on foot can now be skipped over in mere hours using air vehicles, or in a day or two when employing motorized land vehicles. However, sometimes a simpler mode of transport is desired, one without the expense, noise, and congestion often associated with airplanes, cars, snowmobiles, etc.
When it came to movement over land without the use of animals or engines, human powered vehicles were some of the earliest improvements over walking. In colder climates, when snow and ice covered the area to be traversed, humans developed skis and sleds for transportation. In warmer climes, wheeled vehicles such as bicycles eventually became commonplace.
Skis, although useful, have some inherent problems including being somewhat unstable, requiring a certain amount of practice to utilize effectively, and requiring significant energy in order to propel oneself along a flat or inclined surface. Sleds, on the other hand, are much more stable, and require little if any practice to become proficient in their use. However, it can be difficult for a person riding in a sled to push the sled forwards unless it is being used on a slope or there is someone/something pulling or pushing the sled. In order to address this issue, people have long utilized the pulling ability of animals (such as sled dogs, horses, etc.) to move sleds. Alternatively, some sleds have been developed that allow people to kick or otherwise propel themselves without the need for animals. For example, one sled, called a kick-sled, has two long ski-like runners and upright handles that allow a user to stand on the runners and kick between them to propel the sled forwards. Such kick-sleds can be useful on relatively flat ice or snow, but tend to be difficult to maneuver or turn and also rapidly become unsafe when an increasing downward slope is encountered, as they do not have any braking system. The runners built into such sleds are purpose-built and not interchangeable, requiring different sleds when used on different terrain/surfaces, such as powdery snow versus ice.
What is needed is a ski-attachable upright conveyance that allows a person to stand upright, propel themselves across varying terrain, safely control their speed when traveling down-slope, and easily switch skis depending on the terrain and uses to which the vehicle is put. Additionally, the conveyance should be able to be attached to wheels or skates for use in warmer climates or when snow and ice are not present.